Felt hardening machine



June I, 1948. A. J. EVERS FELT HARDENING MACHINE} Filed Sept. 22, 1944 Inn/en i01- ARTHUR J. EVERSI y #AKM Iarney Patented June 1, 1948 UNITED STATES PATENT OFFICE FELT HABDENING MACHINE Arthur J. Evers, Brooklyn, N. Y.

Application September 22, 1944, Serial'No. 555,376

15 Claims.

This invention relates to machines for hardening felt and felt bodies, and particularly to the hardening devices of formers thereof.

Hardening of felt and felt bodies, for example the hardening of hat bodies in felt hat manufacture, is usually accomplished by pressing the felt between relatively oscillating boards or formers in the presence of steam. For many years, the conventional former of such hardening machines has had for its working or felt-engaging surface, a layer of canvas or other water absorbent fabric through which steam could be difiused into and from the felt during the hardening operation.

I have discovered that a greatly improved hardening action is obtained by forming the feltengaging surface of at least one, and preferably both, of the formers of a granular material consisting of discrete granules or grits bonded together into a hard, coherent structure, which is preferably finely porous and pervious to steam or at least moisture-absorbent.

This material may, for example, be ordinary artificial abrasive stone, made of particles of silicon carbide such as Carborundum, or of aluminum oxide such as Aloxite, or of emery or the like bonded together into a hard, stone-like but finely porous structure by a ceramic binder. Such artificial abrasive stone is produced by numerous abrasive manufacturers in a substantially standard range of porosities and, in a range of medium to high porosity, constitutes a preferred material for purposes of the invention. Such stone of medium to high porosity is moisture-absorbent. and freely porous to steam under the moderate pressure, slightly above atmospheric, which it is desirable to use in the hardening operation. Naturally occurring stones may also be employed, for example sandstone or pumice which have the preferred finely porous, moisture-absorbent granular structure. Another suitable type of material is produced by sintering metal granules or grits under controlled conditions to produce an incomplete fusion which binds the grits together into a hard, granular structure. A suitable material of this latter type which is finely porous, moisture-absorbent and steampervious is produced commercially by the Morraine Products Company, of Dayton, Ohio, under the trade designation Porex. Another suitable type of material is unglazed finely porous pottery or earthenware that is moisture absorbent and may be made in many variations of clays and binders.

In the utilization of the invention, sheets or 2 slabs of the granular-material are employed to form the working surface of at least one of the opposed hardening devices or formers of the felt hardening machine. The felt is clamped between the formers and one or both formers are given a rapid oscillating movement parallel to the surfaces of the intervening felt. The requisite heat and moisture are preferably supplied by passing steam under light pressure through the granular material forming one of the working surfaces and into the felt, this operation being permitted by empolying a preferred form of the granular material which is sufficiently porous to pass steam. However, instead, the felt may be thoroughly steamed or sprayed with a fine vapor immediately prior to the hardening operation in order to provide the necessary moisture in the felt. In

either case, it is desirable to employ a granular material which is porous at least to the extent of being moisture-absorbent, since absorbence of moisture into the working surfaces of the formers greatly facilitates the hardening action.

The hardening action produced by the hard, granular surfaced formers of the invention is a very marked improvement over that obtainable with the cloth-surfaced hardening boards of the prior art. A more effective working action on the felt is obtained, producing a harder felt in shorter time. Greater shrinkage is produced and the felt is more uniformly hard. These advantages appear to result in part because the granular material presents a harder, more uniform and efflcient working surface to the felt and, in part, because the finely porous structure of the pre- 1" erred granular material is more evenly moistureabsorptive than a cloth surface, providing a better distribution of moisture over the working surfaces of the formers.

In addition to the foregoing advantages, the granular material is much more durable than cloth surfacing material partly because of greater strength and wear'resistance and partly due to a greater resistance to deterioration by acids such as are frequently present in felt undergoing treatment.

Both the granules and the binder of the granular material, if a separate binder is employed, should be of substances which, as in the cases of the suitable materials previously mentioned, are resistant to softening or deterioration in the presence of moisture or steam, as well, of course, as having the capacity for forming together a hard, coherent structure. Artificial abrasive stone having a ceramic binder is preferred because it possesses these qualities to a high degree, and in most forms, at least, has the preferred porosity characteristics. Uniformity of surface character or roughness and of porosity are desirable characteristics.

In the accompanying drawing the invention is illustrated as applied to a felt hardening machine of a conventional type, the single figure of the drawing showing the machine partially in verti cal section, partially in side elevation.

Referring to the drawing, upper and lower hardening devices or formers are shown at "I and I2, respectively, each having its working or felt-engaging surface formed, according to the invention, of a sheet or slab designated, respectively, l4 and I6, of absorptive steam-pervious granular material such as has been previously described, for example, silicon carbide abrasive stone. Lower 'former l2 comprises a hollow trough-shaped member it, having air tight bottom and side walls. The upper end of this member is closed by the abrasive sheet i6 which is clamped upon a gasket 20 on the upper edges of the member l6 bymeans of clamp lugs 22 embedded at one end in the ends of the material I and bolts 24 passing through apertures in the outer ends of lugs 22 and received in threaded apertures in lateral end extensions 28 of the upper edge of themember l6. Former I 2 is resiliently supported at its ends by coil springs 30 housed in hollow posts 32 on a base 34, these springs bearing at their upper end against collars 3i fastened to bolts 31 which are screw threaded through end extensions 28 of member I! adiustably locked by nuts 38, the bolts 31 being freely vertically slidable in apertures 40 in the upper end of posts 32. At least two of these supports will usually be provided at each end of the former, adjacent opposite sides of the end extension 28,

Steam under light pressure is admitted into the interior of member l8 through a nozzle 42 fastened through the bottom of the member and connected by a flexible hose 44 with a suitable source (not shown) of the steam.

Upper former lil comprises a box-like supporting member 48 having at the bottom thereof spaced frame members 48 to which the granular sheet I4 is fastened by means of bolts 50 screw threaded through the bars and having end lugs cemented in notches 52 out in the upper surface of the sheet. A spider 54 is fastened to the upper end of member 46 and has mounted upon its central portion an upwardly extending lug 56 to which is pivoted one end of intermediately pivoted together toggle levers B pivotally suspended from a fixed support 60 above the machine. One of the levers 58 has pivoted thereto a rod 62 which is connected at its other end to suitable fluid prssure or other mechanism (not shown) for reciprocating the rod endwise for a purpose hereinafter explained.

An arm 64 fast to one end of member 46 is pivoted at its other end to a lug 66 which is vertically slid-able on a bolt 68, between a bracket arm I0 and a slide 12 on which the arm is mounted, the bolt 68. being fastened through bracket arm I0 and the slide. Slide 12 is reciprocated in a guideway I4 by means of a crank arm I! pivoted to the slide and to a crank disk I. on a drive shaft 80.

In the drawing,'the upper former is shown in closed down position in which a layer 'of felt to be hardened will ordinarily be compressed between the slabs i4 and I6. Clamping pressure pressure applied to rod "which holds the toggle leverage 58 in extended position as shown. To harden the felt, shaft II is operated'to oscillate upper former Ill, through crank arm it. slide I2 and arm 84, rapidly parallel to the surface of the felt, longitudinally or from right to left and reverse in the drawing, this oscillatory movement being permitted by the pivot connec@ tions in the clamping leverage. At the same time steam under moderate pressure is continually supplied to the interior of the lower former i2 through nozzle 42 whence it diffuses upwardly through the porous slab ll through the felt and through the porous slab l4 from which it is permitted to escape through the open structure of member 46. Upon completion of the hardening operation, rod 62 is retracted, to the right in the drawing, causing the toggle levers 58 to pivot on their mutual connection into angular relation, raising the former ill by pivoting of arm 04 on its connection to lug It. The hardened felt may then be withdrawn, a new felt inserted, former I0 clamped down and, the operation repeated.

The granular material which is employed for the working surface of the formers is preferably by nature rigid or semi-rigid and has little or no yieldability to adjust itself to irregularities in the thickness of the felt layer. The spring mountings, however, for the lower former, together with the loose connection of arm 84 to bolt 68, permit self adjustment of the spacing and angle of inclination between the abrasive surfaces of the two formers to accommodate varying thicknesses of feltthrough tilting adjustment movements of the formers themselves against the pressure of the springs. Also, as the thickness of the felt diminishes under the hardening action, the springs correspondingly elevate the lower former to maintain a substantially constant clamping pressure of the abrasive surfaces on the felt.

It will be appreciated, of course, that the invention is of general application to felt hardening machines and is not limited to details of mechanism of the particular machine selected for purposes of illustrating the invention.

Having now described the invention, what I desire to claim and secure byLetters Patent is:

1. In a felt hardening machine, opposed hardening members arranged to press and rub between tnem a layer of felt, at least one of said members having a felt-engaging portion formed of abrasive stone the felt-engaging surface of which is abrasive.

2. In a felt hardening machine, opposed hardening members arranged to press and rub bebetween them a layer of felt, at least one of said members having a felt engaging portion formed of moisture absorbent stone the felt-engaging surface of which is abrasive.

3. In a felt hardening machine, opposed hardening members arranged to press and rub between them a layer of felt, at least one of said members having a felt-engaging portion formed of moisture-absorbent abrasive stone comprising a ceramic binder. Y

4. In a felt hardening machine, opposed hardening members arranged topress and rub between them a layer of felt, at least one of said members having a moisture absorptive felt-engaging portion formed of partially fused metallic granules.

5. In a felt hardening machine, opposed hardening members arranged to press and rub between them a layer of felt. at least one of said members having a felt-engaging portion formed of moisture-absorbent granular material comprising metallic granules.

6. In a felt hardening machine, opposed hardening members arranged to press and rub between them a layer of felt, at least one of said members having a f cit-engaging surface composed essentially of grits bonded together into a moisture-absorbent slab of a hardness and roughness comparable to abrasive stone.

7. In a felt hardening machine, opposed hardening members arranged to press and rub between them a layer of felt, at least one of said members having a felt-engaging surface composed essentially of grits and a binder cementing said grits together into a moisture-absorbent slab of a hardness and roughness comparable to abrasive stone.

8. In a felt hardening machine, opposed hardening members arranged to press and rub between them a layer of felt, at least one of said members having a felt-engaging portion comprising. a moisture-absorbent body of abrasive grains the felt-engaging surface of which is abrasive.

9. In a felt hardening machine, opposed hardening members arranged to press and rub between them a layer of felt, one of said members having a felt-engaging portion comprising a steam-pervious and moisture-absorbent body of abrasive grains, and means for passing steam.

through said portion of said member into a felt layer being rubbed between the members.

10. In a felt hardening machine, opposed hardening members arranged to press and rub between them a layer of felt, said members having opposed felt-engaging portions each comprising a steam-pervious body of abrasive grains, and means for passing steam through said portion of one of said members into a layer of felt being rubbed between the members.

11. In a felt hardening machine, opposed hardening members arranged to press and rub between them a layer of felt, at least one of said members having a felt-engaging portion comprising a moisture-absorbent body of bonded granular material.

12. In a felt hardening machine, opposed hardening members arranged to receive between them a layer of felt to be hardened, at least one of said members having a felt-engaging portion comprising a moisture-absorbent body of abrasive grains the felt-engaging surface of which is abrasive, and means for clamping said members together upon an intervening felt layer and for oscillating one of said clamped members parallel to the felt-engaging surface thereof to rub the intervening felt layer between said members.

13. In a felt hardening machine, opposed hardening members arranged to receive between them a layer of felt to be hardened, at least one of said members having a felt-engaging portion comprising a. moisture absorbent body of bonded granular material, and means for clamping said members together'upon an intervening felt layer and for oscillating one of said clamped members parallel to the felt-engaging surface thereof to rub the intervening felt layer between raid members.

14. In a, felt hardening machine, opposed hardening members arranged to press and rub between them a layer of felt, one of said members having a felt-engaging portion comprising a steam-pervious and moisture-absorbent body of abrasive grains.

15. In a felt hardening machine, opposed hardening members arranged to press and rub between them a layer of felt, one of said members having a felt-engaging portion comprising a steam-pervious body of abrasive grains.

ARTHUR J. EVERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES 'PATENTS Number Name Date 12,321 Middlebrook et a1 Jan. 30, 1855 255,261 Doubleday Mar. 21, 1882 381,012 Hawley Apr. 10, 1888 1,272,638 Dulaney July 16, 1918 2,198,620 Irvine Apr. 30, 1940 2,264,158 Clark Nov. 25, 1941 FOREIGN PATENTS Number Country Date 466 Great Britain 1874 487,694 Germany Dec. 13, 1929 OTHER REFERENCES Marks, Mechanical Engineers Handboo 1st ed. 1916, page 385, table 4, columns 1 and 5. 

